fix(e2e): use loopback for host-network supervisor

Signed-off-by: Drew Newberry <anewberry@nvidia.com>

Author: drew

tests/ansible/roles/openshell_gateway/templates/gateway-docker.toml.j2

@@ -7,7 +7,7 @@ socket_path = "{{ openshell_runtime_socket }}"
 default_image = "ghcr.io/nvidia/openshell-community/sandboxes/base:latest"
 image_pull_policy = "if_not_present"
 sandbox_label = "tmachine"
-grpc_endpoint = "http://host.openshell.internal:17670"
+grpc_endpoint = "http://127.0.0.1:17670"
 sandbox_runtime_image = "docker.io/openshell/sandbox:tmachine"
 supervisor_image = "docker.io/openshell/supervisor:tmachine"
 {% endblock %}